On Aug. 1, 2016, officials in Florida announce that 10 more people Florida are infected with the Zika virus. This is in addition to the four cases reported on July 29. So far, the cases seem to be localized to an area just north of downtown Miami. In response, the Centers for Disease Control (CDC) issues an unprecedented travel warning—the first for the continental U.S.—for all pregnant women to avoid that area if possible.